Small boom lifts, for example those less than 15,000 lbs. gross vehicle weight, are generally two wheel drive battery powered machines for indoor use only. The wheels on these machines are primarily driven with electric motors and planetary gearboxes on the non steering axle of the machine. The configuration of this electric drive system is extremely long and makes it impossible to drive the steering wheels because the electric motor extends too far and interferes with the operation of the vehicle by engaging the frame of the vehicle. In addition, because these electric motors are normally in the non-steer axle on an indoor machine, they do not have (or need) any sort of environmental protection.
The major hurdle for putting a hybrid electric system in a large gross vehicle weight machine, prior to the invention described and claimed herein, is that the same type of electric drive assembly used on small boom lifts cannot be used in large boom lifts. Therefore, there is a need for an electric drive assembly that has a higher power density and is environmentally protected. The instant invention solves the problem and answers the need.